Indoor air-conditioning device and container refrigeration device equipped with same

Abstract

A CA system includes a gas supply device which performs a gas supply operation of supplying nitrogen-enriched air into a container, and a controller which performs the gas supply operation so that the inside air has a desired composition. The controller performs carbon dioxide priority control in which the controller performs the gas supply operation if an oxygen concentration of the inside air is equal to or higher than a ceiling concentration higher than a target oxygen concentration, stops the gas supply operation if a carbon dioxide concentration of the inside air is lowered to a critical concentration lower than a target carbon dioxide concentration, and restarts the gas supply operation if the carbon dioxide concentration of the inside air has reached a restart concentration higher than the target carbon dioxide concentration through breathing of the plants.

The invention claimed is: 
     
       1. An inside air control system comprising:
 a gas supply device which includes an air pump and performs a gas supply operation of supplying, by the air pump, nitrogen-enriched air having a higher nitrogen concentration and a lower oxygen concentration than outside air into a storage storing breathing plants; and 
 a controller which controls the gas supply operation so that inside air of the storage has a desired composition, wherein 
 the controller performs carbon dioxide priority control in which
 the controller performs the gas supply operation if an oxygen concentration of the inside air is equal to or higher than a ceiling concentration higher than a target oxygen concentration, stops the gas supply operation if a carbon dioxide concentration of the inside air is lowered to a critical concentration lower than a target carbon dioxide concentration regardless of the oxygen concentration, and 
 restarts the gas supply operation if the carbon dioxide concentration of the inside air has reached a restart concentration higher than the target carbon dioxide concentration through breathing of the plants while the gas supply operation is being stopped. 
 
 
     
     
       2. The inside air control system of  claim 1 , wherein if the carbon dioxide concentration of the inside air is lower than a predetermined onset concentration higher than the target carbon dioxide concentration at an onset of the carbon dioxide priority control, the controller does not perform the gas supply operation until the carbon dioxide concentration of the inside air reaches the predetermined onset concentration through breathing of the plants, and performs the gas supply operation after the carbon dioxide concentration of the inside air has reached the predetermined onset concentration. 
     
     
       3. The inside air control system of  claim 1 , wherein the controller selectively performs the carbon dioxide priority control and an oxygen priority control in which, if the oxygen concentration of the inside air is equal to or higher than the ceiling concentration, the gas supply operation is performed to lower the oxygen concentration of the inside air, irrespective of the carbon dioxide concentration of the inside air. 
     
     
       4. A container refrigeration apparatus comprising:
 an inside air control system of  claim 1 ; and 
 a refrigerant circuit which performs a refrigeration cycle, wherein 
 the container refrigeration apparatus cools inside air of a container serving as the storage, and controls a composition of the inside air. 
 
     
     
       5. An inside air control system comprising:
 a gas supply device which includes an air pump and performs a gas supply operation of supplying, by the air pump, nitrogen-enriched air having a higher nitrogen concentration and a lower oxygen concentration than outside air into a storage storing breathing plants; and 
 a controller which controls the gas supply operation so that inside air of the storage has a desired composition, wherein 
 the controller performs carbon dioxide priority control in which
 the controller performs the gas supply operation if an oxygen concentration of the inside air is equal to or higher than a ceiling concentration higher than a target oxygen concentration, stops the gas supply operation if a carbon dioxide concentration of the inside air is lowered to a critical concentration lower than a target carbon dioxide concentration, and 
 
 restarts the gas supply operation if the carbon dioxide concentration of the inside air has reached a restart concentration higher than the target carbon dioxide concentration through breathing of the plants while the gas supply operation is being stopped, wherein 
 the controller selectively performs the carbon dioxide priority control and an oxygen priority control in which, if the oxygen concentration of the inside air is equal to or higher than the ceiling concentration, the gas supply operation is performed to lower the oxygen concentration of the inside air, irrespective of the carbon dioxide concentration of the inside air, and 
 the controller performs, if the oxygen concentration of the inside air is equal to or higher than the ceiling concentration, a predetermined priority determination to determine which of the oxygen priority control and the carbon dioxide priority control is performed. 
 
     
     
       6. The inside air control system of  claim 5 , wherein the controller determines to perform the carbon dioxide priority control through the priority determination if the target carbon dioxide concentration is higher than a predetermined value. 
     
     
       7. The inside air control system of  claim 5 , wherein the controller determines to perform the carbon dioxide priority control through the priority determination if the sum of the oxygen concentration and carbon dioxide concentration of the inside air is higher than a predetermined reference concentration which is equal to or higher than 21%. 
     
     
       8. The inside air control system of  claim 5 , wherein the controller determines to perform the carbon dioxide priority control through the priority determination if the carbon dioxide concentration of the inside air has increased by a value equal to or higher than a predetermined value in a predetermined period during the gas supply operation. 
     
     
       9. The inside air control system of  claim 5 , wherein the controller determines to perform the carbon dioxide priority control through the priority determination if the power of the inside air control system is turned on within one day of turning of the power of the inside air control system from on to off and the carbon dioxide concentration of the inside air has increased by a value equal to or higher than a predetermined value as compared to the carbon dioxide concentration of the inside air just before the power of the inside air control system was turned off. 
     
     
       10. The inside air control system of  claim 5 , wherein
 the controller sets a carbon dioxide priority flag active if the controller has determined to perform the carbon dioxide priority control through the priority determination, and sets the carbon dioxide priority flag inactive if the controller has determined to perform the oxygen priority control through the priority determination or a predetermined reset condition is met, and 
 the controller determines to perform the carbon dioxide priority control through the priority determination if the power of the inside air control system has been turned from off to on and the carbon dioxide priority flag is active.